Goodwill And Acquisition-Related Intangibles, Net (Narrative) (Details)	6 Months Ended	12 Months Ended
Sep. 30, 2017	Mar. 31, 2017
Minimum
Finite-Lived Intangible Assets
Finite-Lived Intangible Asset, Useful Life	2 years
Maximum
Finite-Lived Intangible Assets
Finite-Lived Intangible Asset, Useful Life	14 years
Weighted Average
Finite-Lived Intangible Assets
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	11 months	1 year 5 months

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

Name:	us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration